For example, in electronic apparatuses such as broadcasting transmitters, a plurality of electronic circuit boards having respective specific processing functions are detachably connected to a plurality of free slots provided in a motherboard in a housing. The motherboard is provided with a transmission line configured to perform signal transmission between the electronic circuit boards connected to the free slots by a differential method.
In the meantime, in the above electronic apparatuses, transmission parameters and reception parameters (such as a signal amplitude, a drive current, a reception gain, and an equalizer) to improve the transmission quality are automatically set for a substrate which has been first mounted to the free slot of the motherboard in the housing, directly after the power of the housing is turned on.
On the other hand, when the board breaks down or the construction is to be changed during operation in the above electronic apparatuses, a new board must be hot-inserted without stopping the operation. When a new board is hot-inserted, however, the power of the housing is not turned on again, and thus parameters are not automatically set. In this case, although the parameter set value of the old board is different from the parameter set value of the new board, automatic parameter setting is not performed. Thus, the operation processing may be disordered simultaneously with hot-insertion of the new electronic circuit board, and the communication quality may be adversely influenced.